#!/bin/sh
#
#
# OCF resource agent to attach a cinder volume to an instance.
#
# Copyright (c) 2018 Mathieu GRZYBEK
# Based on code of Markus Guertler
# All Rights Reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of version 2 of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it would be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# Further, this software is distributed without any warranty that it is
# free of the rightful claim of any third person regarding infringement
# or the like.  Any license provided herein, whether implied or
# otherwise, applies only to this software file.  Patent licenses, if
# any, provided herein do not apply to combinations of this program with
# other software, or any other product whatsoever.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write the Free Software Foundation,
# Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
#

#######################################################################
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs

# Defaults
OCF_RESKEY_openstackcli_default="/usr/bin/openstack"
OCF_RESKEY_node_id_cache_file_default="/tmp/node_id"
OCF_RESKEY_volume_local_check_default="true"

export attached_server_id=""

: ${OCF_RESKEY_openstackcli=${OCF_RESKEY_openstackcli_default}}
: ${OCF_RESKEY_node_id_cache_file=${OCF_RESKEY_node_id_cache_file_default}}
: ${OCF_RESKEY_volume_local_check=${OCF_RESKEY_volume_local_check_default}}

#######################################################################


USAGE="usage: $0 {start|stop|status|meta-data}";
###############################################################################


###############################################################################
#
# Functions
#
###############################################################################


metadata() {
cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="openstack-cinder-volume">
<version>2.0</version>
<longdesc lang="en">
Resource Agent to attach a cinder volume to an instance.
It relies on attributes given by openstack-info resource agent (openstack_id attribute).
</longdesc>
<shortdesc lang="en">Attach a cinder volume</shortdesc>

<parameters>
<parameter name="openstackcli">
<longdesc lang="en">
Path to command line tools for openstack.
</longdesc>
<shortdesc lang="en">Path to Openstack CLI tool</shortdesc>
<content type="string" default="${OCF_RESKEY_openstackcli_default}" />
</parameter>

<parameter name="node_id_cache_file">
<longdesc lang="en">
Path to Node ID cache file, used to avoid Openstack API calls:
1. Is the local file written?
2. Is openstack_id available as a node attribute?
3. Can we get it from the API?
</longdesc>
<shortdesc lang="en">Path to Node ID cache file</shortdesc>
<content type="string" default="${OCF_RESKEY_node_id_cache_file_default}" />
</parameter>

<parameter name="volume_local_check">
<longdesc lang="en">
This option allows the cluster to monitor the cinder volume presence without 
calling the API.
</longdesc>
<shortdesc lang="en">Monitor cinder volume locally</shortdesc>
<content type="boolean" default="${OCF_RESKEY_volume_local_check_default}" />
</parameter>

<parameter name="openrc" required="1">
<longdesc lang="en">
Valid Openstack credentials as openrc file from api_access/openrc.
</longdesc>
<shortdesc lang="en">openrc file</shortdesc>
<content type="string" />
</parameter>

<parameter name="volume_id" required="1">
<longdesc lang="en">
Cinder volume identifier to use to attach the bloc storage.
</longdesc>
<shortdesc lang="en">Volume ID</shortdesc>
<content type="string" />
</parameter>

</parameters>

<actions>
<action name="start" timeout="180s" />
<action name="stop" timeout="180s" />
<action name="monitor" depth="0" timeout="30s" interval="60s" />
<action name="validate-all" timeout="5s" />
<action name="meta-data" timeout="5s" />
</actions>
</resource-agent>
END
}

#
# This is used to get the node ID from different sources:
# 1. Is the local file written?
# 2. Is openstack_id available as a node attribute?
# 3. Can we get it from the API?
#
# When the ID is retrieved, the local cache file is written.
# This prevents the agent to call the API each time the agent is used.
#
_get_node_id() {
	local crm_node
	local node
	local node_id
	local result

	crm_node=$(crm_node -n)

	#
	# Use local cache
	#
	if [ -f $OCF_RESKEY_node_id_cache_file ] ; then
		node_id=$(cat $OCF_RESKEY_node_id_cache_file)
		
		if [ ! -z "$node_id" ] ; then
			echo $node_id
			return
		fi
	fi

	#
	# Query the attributes database
	#
	node_id=$(${HA_SBIN_DIR}/attrd_updater --query -n openstack_id -N $crm_node \
		| tr ' ' '\n' \
		| awk -F= '/value=/ {gsub("\"","");print $NF}')

	if [ ! -z "$node_id" ] ; then
		echo $node_id | awk '{print $1}'
		echo $node_id | awk '{print $1}' > $OCF_RESKEY_node_id_cache_file
		return
	fi

	#
	# Use the API
	#
	node=$(crm_node -n | awk -F. '{print $1}')

	result=$($OCF_RESKEY_openstackcli server list \
		--format value --column ID --column Name \
		| grep $node)

	if [ $? -eq 0 ] ; then
		echo $result | awk '{print $1}'
		echo $result | awk '{print $1}' > $OCF_RESKEY_node_id_cache_file
		return
	fi

	ocf_exit_reason "openstack_id attribute must be set for node $crm_node"
	return $OCF_ERR_CONFIGURED
}

osvol_validate() {
	local node_id

	check_binary "$OCF_RESKEY_openstackcli"
	check_binary "awk"
	check_binary "tr"
	
	. $OCF_RESKEY_openrc

	node_id=$(_get_node_id)

	if [ -z "$node_id" ] ; then
		ocf_exit_reason "openstack_id attribute must be set for node $crm_node"
		return $OCF_ERR_CONFIGURED
	fi

	if [ -z "$OCF_RESKEY_openrc" ]; then
		ocf_exit_reason "openrc parameter not set"
		return $OCF_ERR_CONFIGURED
	fi

	if [ ! -f "$OCF_RESKEY_openrc" ] ; then
		ocf_exit_reason "openrc file not found"
		return $OCF_ERR_CONFIGURED
	fi

	return $OCF_SUCCESS
}

osvol_monitor() {
	local result
	local node_id
	local short_volume_id
	local fdisk_command

	if ocf_is_true $OCF_RESKEY_volume_local_check ; then
		#
		# Is the volue attached?
		# We check the local devices
		#
		short_volume_id=$(echo $OCF_RESKEY_volume_id | awk '{print substr($0, 0, 20)}')
		if uname | grep -q Linux ; then
			fdisk_command="fdisk -l"
		else
			fdisk_command="fdisk"
		fi

		$fdisk_command /dev/disk/by-id/virtio-$short_volume_id 1>/dev/null 2>&1
		if [ $? -eq 0 ] ; then
			return $OCF_SUCCESS
		else
			ocf_log warn "$OCF_RESKEY_volume_id is not attached to instance $(_get_node_id)"
			return $OCF_NOT_RUNNING
		fi
	else
		#
		# Is the volue attached?
		# We use the API
		#
		result=$($OCF_RESKEY_openstackcli volume show \
			--column status \
			--column attachments \
			--format value \
			$OCF_RESKEY_volume_id)

		if echo "$result" | grep -q available ; then
			ocf_log warn "$OCF_RESKEY_volume_id is not attached to any instance"
			return $OCF_NOT_RUNNING
		else
			export attached_server_id=$(echo $result|head -n1|awk -F "'" '{print $4}')
			ocf_log info "$OCF_RESKEY_volume_id is attached to instance $attached_server_id"

			# Compare node_id and the id of the node the volume is attached to
			node_id=$(_get_node_id)

			if [ "$node_id" != "$attached_server_id" ] ; then
				return $OCF_NOT_RUNNING
			fi
		fi
	fi

	return $OCF_SUCCESS
}

osvol_stop() {
	local node_id

	#
	# Is the volume already attached?
	#
	osvol_monitor
	if [ $? = $OCF_NOT_RUNNING ]; then
		ocf_log info "Volume $OCF_RESKEY_volume_id already available"
		return $OCF_SUCCESS
	fi

	node_id=$(_get_node_id)

	#
	# Unmout the volume
	#
	if ! $OCF_RESKEY_openstackcli server remove volume $node_id $OCF_RESKEY_volume_id ; then
		ocf_log error "Couldn't remove volume $OCF_RESKEY_volume_id from instance $node_id"
		return $OCF_ERR_GENERIC
	fi

	ocf_log info "Successfully removed $OCF_RESKEY_volume_id from instance $node_id"
	return $OCF_SUCCESS
}

osvol_start() {
	local node_id

	#
	# Is the volume already attached?
	#
	osvol_monitor
	if [ $? = $OCF_SUCCESS ]; then
		ocf_log info "$OCF_RESKEY_volume_id already attached"
		return $OCF_SUCCESS
	fi

	#
	# Unmout it from another node
	# TODO: make it optional in case multi-attachment is allowed by Cinder
	#
	if [ ! -z $attached_server_id ] ; then
		if ! $OCF_RESKEY_openstackcli server remove volume $attached_server_id $OCF_RESKEY_volume_id ; then
			ocf_log error "Couldn't remove volume $OCF_RESKEY_volume_id from instance $attached_server_id"
			return $OCF_ERR_GENERIC
		fi
	fi

	export attached_server_id=""
	
	node_id=$(_get_node_id)

	#
	# Attach the volume
	#
	$OCF_RESKEY_openstackcli server add volume $node_id $OCF_RESKEY_volume_id
	if [ $? != $OCF_SUCCESS ]; then
		ocf_log error "Couldn't add volume $OCF_RESKEY_volume_id to instance $node_id"
		return $OCF_ERR_GENERIC
	fi

	return $OCF_SUCCESS
}

###############################################################################
#
# MAIN
#
###############################################################################

case $__OCF_ACTION in
	meta-data)
		metadata
		exit $OCF_SUCCESS
		;;
	usage|help)
		echo $USAGE
		exit $OCF_SUCCESS
		;;
esac

if ! ocf_is_root; then
	ocf_log err "You must be root for $__OCF_ACTION operation."
	exit $OCF_ERR_PERM
fi

osvol_validate

case $__OCF_ACTION in
	start)
		osvol_start;;
	stop)
		osvol_stop;;
	monitor|status)
		osvol_monitor;;
	validate-all)
		exit $?;;
	*)
		echo $USAGE
		exit $OCF_ERR_UNIMPLEMENTED
		;;
esac
